Presser member



June 25, 1934. M. H. BALLARD PRES SER MEMBER Filed Jan. 17, 1930Patented June 26, 1934 UNITE STATES FATENT EFICE PRESSER MEMBERApplication January 17,

Claims.

This invention relates to presser members for use in presses for cuttingblanks from sheet material such as leather or canvas and is hereinillustrated as embodied in a sole-cutting ma- 5 chine of the typedisclosed in United States Letters Patent No. 1,194,379, granted August15, 1916 upon an application filed in the name of J. Gouldbourn and A.Bates.

Presses of the type referred to as heretofore constructed comprise apresser member or beam which is reciprocated toward and away from acutting block in applying pressure to a cutting die positioned uponsheet material carried by the block. In machines of this kind which areused for cutting blanks from sole leather or for cutting blanks from aplurality of layers of canvas, the presser member or beam which isusually made of cast-iron has a large cross section in order towithstand the great strains to which the beam is subjected and isconsequently comparatively heavy.

It is an object of my invention to improve machines of the type referredto by providing a novel presser member or beam which, while retainingthe advantages of beams as heretofore constructed, will be comparativelylight in weight but at the same time will have suflicient strength towithstand the hard usage to which it may be put. To this end and asillustrated, the

beam comprises a Striking portion and a strut extending therefrom towhich are connected steel reinforcing members which extend from thestrut to the ends of the beam. The reinforcing members are placed undertension, thereby imparting an initial strain in the striking portion ofthe beam so that the striking portion is deflected in a directon opposedto the direction of application of the load. As a result of this, in theoperation of the press the stresses 4o assumed by the beam in forcing adie through the material will be transmitted to the reinforcing memberswhich will take up the greater part of the stress which would otherwisebe taken by the beam itself. By means of this construction,

comprising reinforcing members which are capable of withstanding greattension, it is possible to utilize a beam of a cross-section ofconsiderably smaller area than would otherwise be the case. The weightof the beam can be still further reduced as in the present instance, byutilizing a light metal such as an aluminum alloy in place of cast-ironas the material for the beam.

The advantages of a light beam constructed as above set forth arenumerous. For example, in

1930, Serial No. 421,576

cutting blanks from sheets of material it is common practice for anoperator to manipulate the starting mechanism of the press in such a waythat the beam is reciprocated toward and away from the cutting blockwith great rapidity, the operator moving the die laterally over thematerial between successive reciprocations of the beam. However, whereheavy beams are used it is common to find that as the operator advancesthe die across the material the speed of reciprocation of the beam isdecreased owing to the fact that the energy stored up in the fly-wheelis decreased to such an extent that the beam is slowed down after anumber of operations in rapid succession. However, with the constructionprovided by the present invention the beam is sufficiently light so thatthe energy required for reciprocating it in producing a rapid sucsessionof pressure applications for forcing dies through the material toproduce blanks will be sufficiently small that there is no appreciableslowing up of the beam in cutting the heaviest material. This results ina more rapid production of blanks and consequent increase in theefiiciency of the machine. Furthermore, the speed of downward movementof the beam will enable the operator to cut blanks from a pile of layersof fabric such as canvas without producing slanting cuts in the lowerlayers of the pile as has heretofore been common. The reason for this isthat the more rapid forcing of the die through the material will avoidthe deformation of the die as it reaches the lower layers of the pile.

The reduced weight of the beam further makes it possible more readily tohandle the beam in assembling it in the machine, and considerablyreduces the amount of vibration during its operation.

Other objects and features of the invention will appear from thefollowing detailed description and claims when taken in connection withthe accompanying drawing, in which Fig. 1 illustrates the upper portionof a press embodying a reinforced beam constructed according to theinvention;

Fig. 2 shows a transverse cross-section of the beam along section IIIIof Fig. 1;

Fig. 3 shows a longitudinal, vertical, cross-sectional view of the beamalong section III-III 105 of Fig. 2, showing the reinforcing members inposition; and

Fig. 4 is a plan view of a portion of the beam showing the arrangementof the reinforcing rods.

As illustrated in Fig. l, the sole-cutting machine comprises a frame 10having a bed 12 supporting a cutting block 14, and a beam 16 which isarranged for reciprocation toward and away from the cutting block inproducing pressureapplying operations upon a die such as die 18. Forsupporting and reciprocating the beam 16 there are provided fourvertical standards 20 slidably mounted in the frame and rigidly securedto the beam at its corners by nuts 22. The standards at opposite ends ofthe beam have their lower ends connected by means of yokes andeccentrics (not shown) to a shaft 24 arranged to be driven by afly-wheel 26 upon operation of a treadle (not shown). For furtherdetails of construction and operation of the parts thus far describedreference may be had to the aforementioned Letters Patent No. 1,194,379.

The beam 16, best shown in Fig. 3, consists in a hollow castingpreferably composed of aluminum alloy and having a striking portioncomprising a plate 28 which has a flat striking surface 30 disposedtoward and parallel to the bed 12. Extending upwardly from the plate 28are side plates 32 which are connected by reinforcing webs 34. Locatedat the central portion of the beam casting is a strut 36 extendingtransversely of the casting and upwardly from the plate 28. The ends ofthe beam are turned upwardly to form flanges 38 also extendingtransversely of the beam.

In order to distribute the stresses caused by application of a load tothe beam, reinforcing members are provided which co-operate with thestrut 36 and flanges 38 to transfer to the ends of the beam stressesapplied to the striking surface 30, particularly at the central portionsthereof. As shown, these reinforcing members comprise rods 40, Figs. 2,3, and 4, preferably composed of steel having high tensile strength,which extend from the flanges 38 inwardly to the strut 36. The innerends 42 of the rods 40 are screwthreaded into a steel cap 44 whichloosely rests upon the strut 36. The outer ends 46 of the rods 40 passthrough the flanges 38 and are secured in position by nuts 48 andwashers 50. The cap 44 being slidable upon the strut 36 provides for theadjustment of the rods longitudinally of the beam in securing the rodsin position. In assembling the reinforcing rods 40 on the beam the nuts48 are taken up to place the rods under considerable tension with theresult that the rods acting through the cap 44 exert pressure upon thestrut 36, and consequently the striking por tion 28 of the beam isdeflected downwardly at the central portions thereof. This is for thepurpose of placing the beam in condition better to withstand the forcesdue to applications of a load acting upwardly against the strikingsurface 30.

In the operation of the machine a die, such as die 18, is placed uponone or more layers of sheet material located upon the cutting block 14,and through the operation of a treadle (not shown) the beam 16 is causedto reciprocate toward and away from the cutting block in apressure-applying operation which results in the forcing of the diethrough the material to form a blank or blanks. Y

In this operation the standards 20 acting at the ends of the beam tendto pull the beam downwardly against a load, which acts between the endsof the beam and results from the resistance encountered by the die inpassing through the material and upper surface portions of the cuttingblock. The load tends to deflect the striking portion 28 of the beamupwardly and consequently to return the striking portion to its normalposition, thereby relieving the strain which was applied to the beaminitially. Stresses which are transmitted from the striking portionthrough the strut 36 and cap 44 tend to force the rods 40 upwardlyagainst the components of the forces in standards 20 which tend to pullthe outer ends of the rods downwardly. This action operates to spreadapart the outer ends of' the rods, placing them under greater tension.Thus, part of the load is taken up by the reinforcing rods withoutincreasing the bending stresses in the remainder of the beam. As theload increases, the striking portion of the beam is deflected upwardlyand the increased stresses are taken up partly by the material of thebeam casting and partly by the reinforcing rods 40 which are placedunder still greater tension.

The employment of reinforcing members constructed and arranged as aboveset forth thus makes it possible to make use of a beam casting of across-section of considerably smaller area than would otherwise bepractical. If desired, the beam may be still further lightened by usinga comparatively light metal, such as aluminum alloy. The decrease in theamount of metal in the beam can thus be effected without sacrificingruggedness of construction and ability to withstand the great stressesto which such beams are subjected.

Typical examples of alloys suitable for use as material for beamcastings of the kind illustrated herein are indicated by the followingapproximate formula:-

(a) 94% aluminum; 4% copper; 1% nickel; 5% manganese; and .5% magnesium.

(b) 89.05% aluminum; 7% zinc; 2.75% copper; 1.2% iron.

The use of a light metal, such as an aluminum alloy composed accordingto one of the formula: above referred to, makes it possible to reduceconsiderably the weight of beams for presses. For example, a nine-footbeam of the shape of that illustrated herein would weigh approximately1300 lbs. if it were composed of cast-iron, whereas a correspondingaluminum alloy beam would weigh approximately 800 lbs.

An advantage resulting from use of a cutting machine equipped with thereinforced light metal beam herein described as compared with the samemachine equipped with a cast-iron beam is that the machine in the formercase can be operated at higher speed under the same power. As a resultof this, the beam thereof can be utilized to produce a succession ofpressure-applying operations upon a die which is moved with greatrapidity across the surface of the material being operated upon, thebeam being sufficiently light that the energy stored up in the fly-wheelis not reduced to the point where the reciprocations of the beam will beappreciably slowed up after a number of pressure-applying operations.

The increased rapidity of reciprocation of the beam is particularlyadvantageous in cutting sheet material comprising several plies offabric such as canvas for the reason that the rapid forcing of the diethrough the material will insure the cutting of blanks of uniform size,the die being forced through the material before its cutting edges canbe forced inwardly which would result in the blanks cut from the bottomof the pile being smaller in size than those cut from the top of thepile.

Having described my invention, what I claim as new and desire to secureby Letter Patent of the United States is:

l. A beam for die presses comprising a casting having a normally flatstriking portion, and means extending freely from the central portion ofthe casting to the ends thereof for placing the striking portion underan initial strain.

2. A beam for die presses comprising a casting having a fiat strikingportion and a strut extending from the striking portion centrallythereof, and a plurality of members forming connections between the endsof the casting and the strut for imparting an initial strain to thestriking portion of the beam.

3. A beam for die presses comprising a casting having a normally fiatstriking portion, the ends of the casting being provided with flangesextending at an angle to said striking portion, a strut extendingtransversely of the casting at the central portion thereof, and membersextending between the strut and the flanges to reinforce the casting.

4. A beam for die presses comprising a casting having a striking portionand rigid strut positioned centrally thereof, a cap loosely mounted uponthe strut, and a plurality of members extending from the cap to the endsof the casting constructed and arranged to place the striking portion ofthe casting under an initial strain.

5. A beam for die presses comprising a casting composed of an alloycontaining a high percentage of aluminum and having a striking portionand a strut extending from the central part of the striking portion, andsteel members extending from the strut to the ends of the strikingportion for reinforcing the casting and for imparting an initial strainto the striking portion of the casting.

MILTON H. BALLARD.

CERTIFICATE OF CORRECTION.

l une 26, 1934.

Patent No. I, 964, 024.

MILTON H. BALLARD.

It is hereby certified that error appears iii the printed specificationof the above numbered patent requiring correction as tollows: Page 3,line 10, claim he said Letters Patent should 2, before "strut insert theward rigid; and that t be read with this earreeticm therein that thesame may conform to the record of the ease in the Patent Giiice.

Signed and sealed this 11th day of September, A. I). 1934.

Leslie Frazer Acting Commissioner of Patents.

(Seal)

